www.igbp.kva.se

The International Geosphere–Biosphere Programme (IGBP):

A Study of Global Change

IGBP is sponsored by the International Council for Science (ICSU)

Issue No. 49April, 2002

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page 20

Science featuresTom Edwards starts this edition by describing recent exciting developments in using water isotopes to

describe and model past and present precipitation (p2). Two ‘marine’ arti-cles follow: Robert Duce and Ed Urban give us an excellent summary of the diverse activities of SCOR (p4); and Stephen Smith describes how the

LOICZ modelling team are successfully implementing a global approach to collect and use data

on C-N-P fl uxes in coastal waters (p7). Carbon is high-lighted again on page 12, where Peter Cox and colleagues explain the importance of incorporating the carbon cycle into general circulation models in order to

increase their accuracy. Finally, Ulrike Lohmann gives us a fascinating insight into how anthropogenic aero-sols affect cloud formation and, ultimately, climate.

Integration SectionIn this Newsletter we introduce a new section; ‘Integration’. The evolving IGBP Phase II places a much stronger emphasis on the integration of different parts of Earth System Science, and on the integration between IGBP and other global change programmes. This regular feature will highlight this important development.

NewsLetter Survey This NewsLetter now reaches 12000 people! Although it is fantastic that we have such a wide readership, the postage is also a major expense. To try and address this problem, we would like to know if you would prefer to receive the newsletter electronically. At the same time we would greatly value your comments on the content and style. Please take a few minutes to fi ll in the enclosed survey!

You have probably noticed immediately that this is not the promised ‘Phase II Special Edition’! We have decided to postpone the special edition until June, in order to ensure that the articles accurately refl ect the complex transition process and the decisions and discussions from the IGBP SC meet-ing in February.

Instead, then, this is a general issue, with fi ve science fea-tures from all corners of IGBP and Earth System Science.

ContentsScience FeaturesMapping and Modelling Global IsotopeClimate and Palaeoclimate ............................................ 2

What is SCOR? ............................................................. 4

Carbon-nitrogen-phosphorusfl uxes in the coastal zone .............................................. 7

Modelling climate-carbon cycle feedbacks .................. 12

Interactions between anthropogenic aerosols and the hydrological cycle ............................ 14

IntegrationThe Twenty-Three GAIM Questions ............................ 20

Human-Environment Interactions ................................ 22

Discussion ForumNatural Sciences + Social Sciences ............................. 24

People and eventsIGBP and Related Meetings ........................................ 27Enclosed

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Science Features

The distribution of the naturally occurring heavy isotopes 2H and 18O in palaeoprecipitation provides one of our most direct and quantitative links to Earth’s past climate and to key aspects of the global water cycle. Palaeoprecipitation isotope data are best known, in the context of global change research, for their use as proxy indicators of palaeotemperature, especially from the exquisitely detailed records of δ2H and δ18O measurements (see Box) obtained from the ancient precipitation preserved in polar glaciers. Some of these records, such as the Vostok record of Antarctica, extend more than 400,000 years into the past, chronicling repeated episodes of continental glaciation (Figure 1). Myriad records spanning shorter periods have also been derived from speleothems, tree rings, lake sediments and numerous other natural isotopic archives.

Mapping and modelling global isotope climate and palaeoclimate

by T. W.D. Edwards

Precipitation isotope data are also widely used in hydrologic studies, exploiting the system-atic spatial and temporal vari-ations in the distribution of water isotopes as input func-tions for investigations rang-ing from assessment of runoff generation processes to the water balance of major river basins.

A relatively recent and exciting development, fuelling demand for much better char-acterisation of the present and past global precipitation isotope fi elds, is the incor-poration of water isotope diagnostics into atmospheric general circulation models - “isotopic-AGCMs”. These models explicitly account for the slightly differing proper-ties of 1H1H16O, 1H2H16O and 1H1H18O, and are thus rigor-

Figure 1. Hydrogen-isotope record obtained from the Vostok ice-core, Antarc-tica (Petit et al. 1999). The record clearly shows the characteristic saw-tooth pattern of glacial-interglacial cycling, refl ecting the grad-ual onset (progressively declining δ2H values) and rapid culmination (abruptly increasing δ2H values) of four major episodes of global con-tinental glaciation, plus many higher-frequency variations. Although this measured isotopic time-series is commonly portrayed as a pal-aeotemperature history, it actually provides a direct chronicle of dynamic changes in the partitioning of isotopes in the global water cycle, which can be mapped with increasing fi delity by isotopic-AGCMs.

Data archived at the World Data Centre for Paleoclimatology, Boul-der, CO, USA: http://www.ngdc.noaa.gov/paleo/data.html

ously constrained by the need to conserve both mass and iso-topes in the global water cycle. This not only imposes espe-cially severe requirements on the realism with which such climate models must mimic nature, but also affords unprec-edented opportunities for direct quantitative comparison of model results with measured isotopic data. The link to the isotopic composition of pal-aeoprecipitation is particularly important, since it will ulti-mately permit use of palaeodata directly, without the additional uncertainties introduced by transformation into secondary proxies like palaeotemperature.

Scientists engaged in ISOMAP, an initiative of the IGBP PAGES core project, have

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Figure 2. Contour maps of the modern global precipitation δ2H fi eld for January, April, July and October, based on the IAEA/WMO GNIP database (see IAEA 2001 for the full set of global and regional maps and animations). These maps represent our current best approximation of the average “climatological” δ2H fi elds for these months over the past 40 years. Key aspects of seasonal water isotope cycling are evident, including the marked deepening in winter and shallowing in summer of the degree of 2H depletion in Arctic precipitation, which is the analogue at annual time-scale of glacial-interglacial signals like those recorded in the Vostok ice core (Figure 1).

Box : What are δ values?The relative abundances of the rare heavy isotopes 2H and 18O or, more correctly, the relative abundances of the water isotopomers that contain them, 1H2H16O and 1H1H18O, in relation to common light water, 1H1H16O, are usually expressed as “δ” values, refl ecting differences in 2H or 18O concentration from that of Vienna Standard Mean Ocean Water. VSMOW approximates the isotopic composition of the world oceans, the primary source of atmospheric moisture and a logical “starting point” in the global hydrological cycle. Rain-out and distillation of moisture during transport to higher latitudes causes progres-sive heavy-isotope depletion (more negative δ values) because of mass-dependent differ-ences in the behaviour of the water isotopomers.

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Further Reading and Web LinksEdwards TWD. (1998). ISOMAP - Reconstructing the Isotopic Composition of Past Precipitation from Continental Archives. PAGES Newsletter 6, 10. (http://www.pages-igbp.org)

Jouzel J, Hoffmann G, Koster RD and Masson V. (2000). Water isotopes in precipitation: Data/model comparison for present-day and past climates. Quaternary Science Reviews 19, 363-379

Petit JR, Jouzel J, Raynaud D, Barkov NI, Barnola J-M, Basile I, Benders M, Chappellaz J, Davis M, Delayque G, Delmotte M, Kotlyakov VM, Legrand M, Lipenkov VY, Lorius C, Pépin L, Ritz C, Saltzman E and Stievenard M. (1999). Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, 429-436

Rozanski K, Johnsen SJ, Schotterer U and Thompson LG. (1997). Reconstruction of past climates from stable iso-tope records of palaeo-precipitation preserved in continental archives. Hydrological Sciences Journal 42, 725-745

Rozanski K, Araguás-Araguás L and Gonfi antini R. (1993). Isotopic patterns in modern global precipitation. In Climate Change in Continental Isotopic Records. Edited by PK Swart, KL Lohmann, J McKenzie and S Savin. Geophysical Mono-graph 78, American Geophysical Union, Washington, DC, p 1-37

Schotterer U, Oldfi eld F and Fröhlich K. (1996). GNIP - Global Network for Isotopes in Precipitation, PAGES, Bern, 48 pp

IAEA (2001). GNIP Maps and Animations, International Atomic Energy Agency, Vienna. (http://isohis.iaea.org)

What is SCOR?by R. Duce and E. Urban

The Scientifi c Committee on Oceanic Research (SCOR) pro-motes international cooperation in oceanography. It was cre-ated by ICSU in 1957 as the fi rst of its interdisciplinary bodies, and operates primarily through three types of scientifi c activities—large-scale research projects, working groups, and advisory bodies and planning groups—supplemented with capacity-building activities.

Global-scale issues related to the role of the ocean in environmen-tal change are tackled through SCOR’s participation in plan-ning and guiding long-term,

taken a lead role in the chal-lenge of mapping and model-ling global isotope climate and palaeo climate. A fi rst step in this endeavour is the fuller characterisation of the present global isotope fi eld for compar-ison with isotopic-AGCM sim-ulations of equilibrium isotope climate under modern bound-ary conditions (Figure 2), and ongoing work is aimed toward mapping and modelling of both equilibrium and transient global isotope climate for key times and intervals in the past. Such efforts will signifi cantly enhance our understanding of past and present global climate history and dynamics, as well as our ability to simulate and anticipate future change using climate models.

Thomas W.D. EdwardsPAGES Visiting Scientist,

Department of Earth Sciences,University of Waterloo,

CanadaE-mail: twdedwar@sciborg.

uwaterloo.ca

large-scale international ocean research projects. For example, SCOR initiated the Joint Global Ocean Flux Study (JGOFS) and the Global Ocean Ecosystem

Dynamics project (GLOBEC; also co-initiated by the Intergov-ernmental Oceanographic Com-mission [IOC]). SCOR and IGBP presently co-sponsor four major ocean science activities. In addi-tion to JGOFS and GLOBEC, these include the now-develop-ing Surface Ocean-Lower Atmo-sphere Study (SOLAS) and the Ocean Biogeochemistry and Ecosystems activity.

In addition to these projects with IGBP, SCOR also co-spon-sors the Global Ecology and Oceanography of Harmful Algal Blooms program (GEOHAB), with IOC. Large-scale blooms of phytoplankton that are toxic to marine organisms or humans, or which lead to oxygen depletion in coastal waters, have become

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a major concern for most coastal nations. Blooms of harmful algae are thought to be related to increased inputs of nutri-ents to coastal waters, but many other factors, includ-ing interacting chemical, biological, and physical con-ditions, infl uence the initi-ation and development of harmful algal blooms by mechanisms that are not well understood. SCOR and IOC are planning for a major international research pro-gram that will study harmful algal blooms from perspectives ranging from why the biology of certain species makes them harmful to how large-scale oceanographic conditions can either promote or hinder blooms.

Working GroupsMore specifi c ocean science topics are addressed by short-lived Working Groups, the tra-ditional mechanism by which SCOR has operated since its inception. Existing working groups focus on a range of scien-tifi c questions:

Biogeochemistry of iron in seawaterIn what forms does iron exist in seawater and what are its

Figure 1. Dust storms deliver materials to the Atlantic Ocean from the Sahara Desert. Photo provided by the SeaWIFS project, NASA/GFSC, and ORBIMAGE.

sources, how does it change among forms, how is it dis-tributed in the ocean, what con-trols iron’s availability to marine organisms, and how should iron best be measured in seawater?

Coastal ocean modellingWhat are the weaknesses of coastal wave models, coastal circulation models, and coastal atmospheric boundary layer models operated separately, and how could they be coupled to produce more realistic and useful results?

Fluid fl ow through coastal sediments What is the magnitude and dis-tribution of submarine ground-

water discharges in space and time, how do such discharges affect coastal nutrient and con-taminant concentrations, and how do they contribute to coastal ocean processes? What reactions and transport phenom-ena are important in different marine environments that con-tain permeable sediments, for example, beach, inter-tidal, sub-tidal, and continental shelf envi-ronments?

Evolution of the Asian mon-soon systemWhat are the key climate proxies necessary for effective compar-ison of the Indian and East Indian monsoon subsystems in their evolution over different time scales in response to tectonic processes, variations in Earth’s orbit, and ocean circulation?

Synthesis of climate records of the past 80,000 yearsAre the records of short-term climatic events in marine sed-iments compatible, as recorded by proxies of isotopic, elemental, palaeontological, sedimentologi-cal, and magnetic properties?

The role of marine phyto-plankton in global climate regulation How do environmental factors (e.g., nutrients, grazing by zoo-plankton) and species-specifi c factors (e.g., genetic composition and cellular responses to envi-ronmental conditions) affect the production of climate-relevant gases, such as the production

of dimethyl sulphide by the phytoplankton species Phaeo-cystis?

New methods

• Surveying plankton: How can strategies for contin-uous sampling of phy-toplankton and sampling instruments be improved and integrated with direct plankton sampling approaches?

• Estimating downward carbon fl ux from the sur-face ocean: How do the carbon export fl uxes deter-mined by sediment trap and Thorium-234 methods differ, what are the main causes of any discrepan-cies, and how can they be resolved? Can Tho-rium-234 serve as a survey tool to determine carbon export fl uxes on a global scale?

• Measuring the status of marine ecosystems: What new indicators could be used to study the func-tional role of species in marine ecosystems and the

“What new indicators could be used to study the functional role of species in marine ecosystems and the effects of exploitation and environment?”

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ulated by the Kyoto Protocol, some commercial enterprises have teamed with ocean scien-tists to design potential schemes to fertilise the surface ocean with iron or nitrogen to create blooms of phytoplankton, which may sink to the deep sea and remove (at least temporarily) carbon from the surface ocean. Others projects are testing tech-niques to inject carbon dioxide into the deep ocean with the hope that it will not return to the atmosphere for several cen-turies. Although much relevant research has been conducted in the past decade, the potential effectiveness and risks of these forms of carbon sequestration in the ocean have not been dis-cussed among ocean scientists as a community recently. SCOR

and IOC are currently planning and raising fi nancial support for an international workshop to document what we know and need to know related to the proposals to attempt to sequester atmospheric carbon dioxide in the ocean through fertilisation of surface waters and deep-ocean injection.

Southern Ocean Research Coordination—Many nations support oceanographic research in Southern Ocean areas, but most programs tend to focus on single disciplines, with little integration among the disci-plines. This can lead to overlaps or gaps among activities that can waste research resources

human activities each year. Sev-eral different national and inter-national programs worldwide make observations of inorganic carbon in the ocean, but ques-tions remain about the spatial and temporal aspects of absorp-tion and release of carbon dioxide by the ocean, how much carbon is exported from the surface ocean to deeper waters, and the effects of increasing carbon dioxide on oceanic biology and chemistry. Key issues that are not routinely han-dled by individual projects involve how to integrate carbon-observing systems and how to standardise measurement techniques and provide reliable reference stan-dards. This panel is responsible to advise global carbon research and monitoring programs on observations, data management, and modelling needed to under-stand the ocean component of the global carbon cycle, and to provide an international forum for initiatives to promote high-quality observations of the ocean carbon cycle. SCOR and IOC have maintained joint activities on the topic of ocean carbon since 1979.

Ocean Carbon Sequestra-tion—As interest in tradable carbon credits has been stim-

Figure 2. High-biomass “red tide” caused by Noctiluca bloom in New South Wales, Australia.

Photo reproduced with permission from Gilbert PM + Pitcher G (eds) 2001. GEOHAB Science Plan.

“What do we need to know before we attempt to sequester atmospheric CO2 in the ocean through fertilisation of surface waters and deep-ocean injection?”

effects of exploitation and environment (e.g., output of multi-species models or available time series, satel-lites, and geographic infor-mation systems)? How can such indicators be used in a comparative way to characterise ecosystem states, changes, and func-tions? What is the utility of these indicators for man-agement purposes and for the sustainable use of renewable marine resources?

• Observing marine life: What are the relative merits of different technol-ogies for observing marine organisms and which tech-nologies deserve further research based on their potential for making sig-nifi cant contributions to the detection of marine life?

Planning Groups and Advisory BodiesThe third type of SCOR activity includes planning groups and advisory bodies:

SCOR-IOC Advisory Panel on Ocean Carbon Dioxide—The ocean absorbs approximately one-third of the carbon dioxide added to the atmosphere by

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or hinder our understanding of how the Southern Ocean works as an integrated system. SCOR is leading a planning activity among international organisa-tions and research projects to coordinate ongoing and planned research in the Southern Ocean.

Capacity-Building Activities

In addition to its scientifi c activ-ities, SCOR conducts an active program of capacity building for developing nations and nations with economies in transition.

Such nations conduct signifi cant ocean research programs on national and regional scales, but are often under-represented in major international ocean research projects. SCOR attempts to increase the involve-ment of scientists from such countries by awarding travel grants for their scientists to par-ticipate in ocean science meet-ings. SCOR also participates in a fellowship program designed to promote ocean observations (led by the Partnership for Observa-tions of the Global Ocean).

Robert A. DuceSCOR President

E-mail: rduce@ocean.tamu.edu

Ed UrbanSCOR Executive Director

E-mail: scor@jhu.edu

Carbon-nitrogen-phosphorus fl uxes in the coastal zone: the global approach

by S.V. Smith, on behalf of the LOICZ Modelling Team

Carbon is generally considered to be the “major currency” within the IGBP, and the nitrogen and phosphorus cycles are intimately linked to carbon. The role of the coastal oceans in global carbon-nitrogen-phosphorus cycles is one of the major and most chal-lenging questions that LOICZ is evaluating. Unlike much of the IGBP, the “domain” of LOICZ (nominally 200 m below sea level to 200 m above sea level, with emphasis on the reactions within the marine portion of the strip) is tremendously diffi cult to describe in detail. Because the zone is relatively narrow (visualise a strip of coastal real estate that is about 500,000 km in length but only averages about 50 km in width), it is not well represented in gridded global data bases. Further, the zone is heterogeneous both along the length of this strip and across its width.

Arguments can be made that both the large load of materials from land and the human infl u-ence along the seashore cause much of the net reaction of this zone to occur in bays and estuar-ies along the landward margin of the strip. The region is not well represented as an extension of oceanic processes up onto the shelf and into the bays and estu-aries, because the infl uence of both bottom chemical reactions and terrestrial inputs (including

especially those associated with human activities) render this region very different from the open ocean. Much of IGBP deals primarily with vertical fl uxes: land-atmosphere, ocean-atmosphere. While LOICZ is concerned with these vertical fl uxes, it also deals heavily with the horizontal fl ux of material from land, largely through lat-eral fl ow of water to the shore-line, and then lateral transport away from the shoreline.

Analytical Methods and a Strategy for

ProgressWithin the limits of these con-siderations, the LOICZ project set up a “globally applicable” method of estimating fl uxes within the coastal ocean, espe-cially the bays and estuaries of the inner coastal zone. It was necessary to erect a methodol-ogy that could depend largely on secondary data, because, within the time span of LOICZ, funding was not likely to be available for collecting signif-icant amounts of new data. Secondly, if the methodology were to be useful for most of the coastal zone, the data requirements had to be minimal. Thirdly, in order to allow effec-tive comparison among sites, the methodology had to be widely applicable and uniform, rather than tailored to specifi c sites. Finally, it was deemed desirable that the method be informative, at some level, about processes infl uencing carbon-nitrogen-phosphorus (CNP) fl uxes.

The LOICZ approach [1, 2] is based on one of the most funda-mental concepts of the physical sciences: conservation of mass.

More informationAdditional information about SCOR and the activities described above can be obtained from the SCOR Web site (www.jhu.edu/~scor) or from Ed Urban.

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Briefl y, the procedure is as fol-lows. Water volume and salt content in the system remain constant over time, as water fl ows through the system and mixes with adjacent systems. The net fl ow of water can be described by a water budget. Information about mixing can be deduced from a salt budget of non-reactive materials. The data to establish at least crude water and salt budgets can be found for many sites around the globe.

Nutrients not only move with the water but also undergo reactions within the system. Nutrient data (especially data on the dissolved inorganic forms of phosphorus and nitrogen, here termed DIP and DIN) can be found for many of these same sites and used to establish nutri-ent budgets. These nutrient bud-gets include the water fl ow and mixing, as defi ned by the water and salt budgets, and an addi-tional term that describes net uptake or release of these nutri-ents within the system. In the jargon of oceanography, these are termed “nonconservative fl uxes,” because the nutrients do not exactly follow the fl ux path-ways of water and salt.

The nonconservative fl ux of DIP can be used as an approxi-mation of net uptake of phos-

phorus into organic matter during primary production or release from organic matter by respiration. The DIP fl ux is scaled to an estimated carbon fl ux via a scaling ratio (typically a molar C:P ratio of 106:1, rep-resenting the so-called “Redfi eld Ratio”). While it would be desir-able to have direct measurement of carbon uptake into organic matter, such data are not avail-able for most locations. There-fore, the fl ux of DIP becomes a proxy for net carbon fl ux. The primary shortcoming of this proxy is that systems with high amounts of suspended mineral material (e.g., from turbid rivers) may show evi-dence for DIP adsorption onto the particulate materials or desorption from them.

In the open ocean DIN is often scaled in exactly this manner to carbon. That scaling in general does not work well in the coastal ocean, for a reason that contains a great deal of information itself. Nitrogen fi xation and denitrifi cation are important metabolic processes in bottom-dominated systems and can account for most of the observed nonconservative fl ux of DIN. Therefore, calculations derived from the budgets use DIP fl ux as a proxy to calculate

how much net carbon uptake or release has occurred, scale this to expected nitrogen fl ux (typically using the Redfi eld N:P ratio of 16:1), and then use the deviation between the observed DIN fl ux and the expected fl ux to esti-mate the net of nitrogen fi xation and denitrifi cation. As is true with carbon, it would be desir-able to have “direct measure-ments” for these important nitrogen fl uxes—and the global data are extremely limited. As is also true in the use of DIP as a carbon proxy, the mineral reactions involving DIP are probably the greatest short-coming of the DIP proxy for nitrogen metabolism. Despite these limitations, semi-quanti-tative insight is gained into the rates of the processes of primary production minus res-piration (abbreviated [p-r]) and nitrogen fi xation minus denitri-fi cation [nfi x-denit].

To implement this process globally, a two-part strategy has been used to acquaint the sci-entifi c community with the bud-geting procedures:

• A web page has been set up [2] that summarises and updates the budgeting procedures, provides tools for implementing the pro-cedures, provides various forms of teaching mate-rials, and posts existing budgets as they are devel-oped.

• A series of workshops has been held around the world in order to teach people how to do the bud-gets and to get them to prepare budgets that can be used by LOICZ.

As a result, about 200 site bud-gets have now been developed (Figure 1) by nearly 180 people and posted on the web pages. Figure 1. The Global Network of LOICZ budget sites, January 2002.

Coastal zone researchers from around the world now repre-sent some of their nutrient budgeting results within a common conceptual framework.

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Beginning to Synthesise the

Results—Spatial Scaling of Available

Budget DataThis article considers some spa-tial scaling issues with respect to nutrient fl uxes in the coastal zone. The budget sites (Figure 1) vary dramatically in their characteristics: from lagoons and estuaries less than 1 km2 in area, to the 106 km2 East China Sea; from sites that are decimetres deep to sites that are hundreds of metres deep; from sites that are virtually devoid of loading from land to sites that receive heavy loads of inorganic nutri-ents derived from human wastes, agriculture, and other sources; from sites that are river-dominated estuaries to hypersa-line embayments; from tropical to arctic climate zones. For some sites data quality and quantity are both high; other sites suffer in the quality and quantity of information available.

Such a wide diversity of site descriptions and data quality poses signifi cant challenges to comparison, and that compara-tive effort is presently under-way. For the present analysis we have set aside systems for which the basic data are incomplete, open shelf systems, and sys-tems with an average depth >100 metres, in order to facilitate comparisons among sites. This parsed data set includes about 80 systems. The remainder of this section is devoted to a brief overview of material loads from land to the coastal zone, exchange between the inner coastal zone and offshore waters, and some characteristics of net biogeo-chemical fl uxes.

Figure 2 illustrates frequency distributions of the apparent

rates of production minus respi-ration [p-r] and nitrogen fi xation minus denitrifi cation [nfi x-denit] as calculated from the nonconservative nutrient fl uxes for these systems. Note that these are net rates, the difference between storage and release processes. These net rates are more relevant than

gross rates to evaluating the role of coastal systems in carbon-nitrogen-phosphorus exchange. The rates cluster near 0 for both [p-r] and [nfi x-denit]. Fur-ther analysis will be required in order both to extrapolate from

these individual site measure-ments to estimates of net metab-olism for the global coastal zone and to evaluate the regional distributions of these rates. In the meantime, further insight into comparisons can be derived from these data.

Figure 3 illustrates terrestrial nutrient loading to the budget

sites. In order to allow com-parison across sites, the data have been normalised to the budgeted area of the receiving water bodies. Two important aspects emerge from this fi gure. First, the area-normalised loading spans 3-4 orders of mag-

nitude. Nutrient loading at the low end of the range is roughly equivalent to upward mixing of nutrients from the deep ocean to the oligotrophic mid-latitude gyres of the surface ocean. At

Figure 2. Frequency distributions of [p-r] and [nfi x-denit] at the budget sites.

[p-r] is primary production minus respiration

[nfi x-denit] is nitrogen fi xation minus denitrifi cation.

“...the LOICZ project set up a “globally applicable” method of estimating fl uxes within the coastal ocean.”

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the other extreme, the high loads are roughly equivalent to direct waste discharge from one person for every 30 m2 of area budgeted! Clearly this range of conditions imposes dramatic differences on the water bodies receiving these loads.

A second important aspect of this loading pattern is that the DIN:DIP loading ratio changes by a factor of about 4 over the loading range. This changing loading ratio repre-sents a change from both low loading and high N:P loading ratio for oligotrophic systems not dramatically infl uenced by human activities, to both higher loading and lower load-ing ratio under the infl uence of human waste discharges. DIN:DIP fl ux ratios of around 30:1 typify discharge from rel-atively pristine river systems, while values near 10:1 typify domestic waste discharge.

Net nutrient reactions in coastal ecosystems clearly respond to nutrient load. The upper panels of Figure 4 dem-onstrate that in general, as nutri-ent load goes up, the absolute values of nonconservative fl uxes increase. DIP and DIN behave somewhat differently. At low DIP

loads nonconservative fl ux is near 0; at loads in excess of about 0.01 mmol m-2 d-1, nonconserva-tive DIP fl ux may become either positive or negative, refl ecting either uptake or release within the systems. Nonconservative DIN fl ux also responds to load-ing; as DIN loading increases

above about 1 mmol m-2 d-1 sys-tems tend to take up DIN.

Coastal ecosystems not only receive inputs from land but also exchange water with the adjacent ocean. The ocean water may have a range of nutrient levels, but these levels typically approx-imate natural oceanic nutrient concentrations. Usually this water is low in both DIN and DIP, relative to the terrigenous load, and has an N:P ratio of <10. Water exchange time is a measure of the time it takes for the coastal water body of interest to exchange its volume with the

adjacent ocean. Exchange time is expressed as the ratio of water volume in the system of interest to the sum of water fl ow through the system plus mixing between the system and adjacent water. The budgeted systems have exchange times ranging from <1 day to several years. The lower

panels of Figure 4 demon-strate that water exchange times of <100 days generally promote more rapid noncon-servative DIP and DIN fl uxes.

Where to from here?

These sorts of scaling analyses are useful for generalising loading, internal reaction, and exchange of materials in coastal ecosystems. However, the data are inevitably biased by the avail-ability of sites for which budget-ary analyses are possible. The next challenge of the analysis is to extrapolate these site-specifi c results to the global coastal zone. Towards this end, the budgeting group is working closely with the typology group in LOICZ [3] in order to accomplish this extrap-olation. The combined typology and budgeting studies have led to an initial “global synthesis

“...high nutrient loads are roughly equivalent to direct waste discharge from one person for every 30 m2 of area budgeted!”

Figure 3.

Area-normalized DIP load versus DIN load to the budget sites. The N:P load-ing ratio diminishes as total load increases

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workshop” that was held in Lawrence, Kansas, in November 2001. Analyses of the geo-spatial global settings, functional pro-cesses in the form of land-derived and oceanic loadings that infl uence the coastal sys-tems, and development of models describing system response relationships provided important milestones and des-tination points in the longer journey of up-scaling; further analyses are proceeding. A report on these interim fi ndings is in preparation and there will also be a chapter in the LOICZ synthesis book encompassing subsequent global and regional integration. A preliminary draft of that book will be prepared in 2002.

AcknowledgementsThere have been literally dozens of contributors to this effort (see

Figure 4. Non conservative nutrient fl uxes in response to nutrient loading (top panels) and water exchange time (bottom panels). Absolute rates of nonconservative fl uxes are higher at high loads and short exchange times.

the list of contributing authors, on the LOICZ Modelling web page [1]). The core team consists of: S. Smith, F. Wulff, D. Swaney, V. Dupra, V. Camacho, L. David, M. McGlone, H. Waldron. In addition, we have close inter-action with the Typology Team (headed by R. Buddemeier) and from the LOICZ International Project Offi ce (C. Crossland et al.). We also acknowledge sup-port from institutions that hosted workshops, the Netherlands gov-ernment agency WOTRO and the GEF programme of UNEP.

Stephen V. SmithSchool of Ocean and Earth Science and

TechnologyUniversity of Hawai’i

USAE-mail: svsmith@soest.hawaii.edu

References1. Gordon Jr. DC, Boudreau PR, Mann KH, Ong J-E, Silvert WL, Smith SV,

Wattayakorn G, Wulff F and Yanagi T. (1996). LOICZ Biogeochemical Mod-elling Guidelines. LOICZ Reports & Studies No 5, 1-96

2. LOICZ Modelling web page: http://data.ecology.su.se/MNODE

3. Buddemeier RW and Maxwell BA. (2000). Typology: Low-budget Remote Sensing. LOICZ Newsletter No. 15, June 2000

This article was fi rst published in the LOICZ newsletter (No. 21, Dec 2001).

More informationFor more information on LOICZ, see: http://www.nioz.nl/loicz

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Modelling climate - carbon cycle feedbacks: a cross disciplinary

collaboration priorityby P. Cox, P. Friedlingstein and P. Rayner

The carbon cycle and climate are tightly coupled. The most obvious illustration of this is provided by the ice-core records which show atmospheric carbon dioxide and global tempera-tures varying together over glacial cycles. Climate also affects the Earth’s carbon cycle on the shorter timescales associated with seasonal cycles and interannual climate variations such as El Niño. Similarly, the carbon cycle is capable of affecting the climate through changes in the concentration of the green-house gases, carbon dioxide and methane. Despite these known links between climate and the carbon cycle, General Circulation Model (GCM) projections of future climate have typically neglected climate-carbon cycle feedbacks. The fi rst attempts to include the carbon cycle as an interactive element of climate models suggest that these longer-timescale interac-tions could produce signifi cant feedback on climate change over the next century.

Carbon budget studies show that only about a half of the cur-rent human emissions of CO2 remain in the Earth’s atmo-sphere. The remainder is being absorbed by the oceans and by vegetation and soil on the land, but in both cases the pro-cesses involved are known to be sensitive to climate. GCM cli-mate change simulations typi-cally use prescribed scenarios of increases in atmospheric CO2, which are derived ‘off-line’ neglecting the potential impacts of climate change on the carbon cycle. These simulations have therefore excluded the effects of feedback between climate and the carbon cycle.

Two recent GCM experi-ments have instead treated atmospheric CO2 as an internal variable, calculating its evolu-tion based on emissions and modelling uptake by land and ocean as a function of the cli-mate. This advance has been strongly supported by IGBP

Figure 1. Climate-carbon cycle GCM experiments carried out at the Hadley Centre (continuous lines) and the Pierie Simon Laplace Institute (IPSL) (dashed lines). Results are shown from runs both with and without carbon cycle feedbacks (red and bluelines respectively).

Reproduced with permission from Nature (Cox et al (2000) Nature 408 : 184-197) Copyright 2000 McMillan Magazines LTD.

projects devoted to the develop-ment and testing of ocean and land carbon models. Both cou-pled GCM experiments show

accelerated climate change as a result of suppression of the land carbon sink, but the magnitude of the effect differs markedly. The Hadley Centre coupled cli-mate-carbon cycle model pro-duces about 250 ppmv higher CO2 concentrations by 2100, compared to an experiment with the same GCM in which climate and carbon cycle are decoupled [1]. As a result the climate warming predicted for the 21st century is much more rapid than previously mod-elled. This positive feedback is associated with the conversion of the global net land carbon sink to a source by the middle of the 21st century. A similar set of numerical experiments car-ried out at the Pierre Simon Laplace Institute (IPSL), France [2] shows a smaller increase of 75 ppmv in the atmospheric CO2 projected for 2100 (see Figure 1).

The reasons for these dif-ferent responses are still under investigation, but it seems that

13

differences in ocean carbon uptake, regional climate change and terrestrial model responses all play a part (Figure 2). For example, the Hadley Centre model produces a relatively weak ocean uptake and a large warming and drying in Amazo-nia under enhanced CO2, which leads to dieback of the tropical forest releasing carbon to the atmosphere. A smaller tropical drying is seen in the IPSL model, which also has much stronger ocean uptake. Both models produce reduced soil carbon (relative to experiments without climate-carbon cycle feedback) but this effect is dependent on uncertain factors such as the assumed sensitivity of soil respiration to temper-ature and the fraction of the total soil carbon which can be readily decomposed by micro-organisms.

The experiments to date suggest in particular that the response of the land biosphere to climate change represents a zeroth-order uncertainty in cli-mate predictions. It is therefore vital that we identify the key uncertainties, and then work with our colleagues from eco-logical and climate disciplines to reduce these. The coupling of physical climate models with models of the biosphere is clearly a cross-disciplinary activ-ity which requires expertise encompassed by both the World Climate Research Programme (WCRP) and the IGBP. The most fruitful way to bring life to the GCM land surface will be to make use of the fi ndings gained in both communities, to produce models which consistently treat the cycling of energy, water, carbon and nutrients within the Earth System. For the land sur-

face this will entail combining the short-time scale components included in GCM land surface schemes with the longer-times-cale components modelled by Dynamic Global Vegetation Models (DGVMs).

A fi rst stage will be to pro-duce a better sample of possible climate carbon cycle feedbacks by encouraging other groups to include interactive carbon cycles within their GCMs. The Coupled Climate Carbon Cycle Model Intercomparison Project (C4MIP) is a joint initiative of IGBP-Global Analysis Integration and Modelling (GAIM) and the WCRP-Working Group on Cou-pled Models (WGCM). C4MIP will provide a framework for the intercomparison of coupled cli-mate-carbon cycle models and ultimately an assessment of the dominant sources of uncer-tainty.

Figure 2. The three panels compare the evolution of atmospheric carbon dioxide (top right), and the ocean and land uptake as a fraction of the emissions (lower 2 panels).

14

carbon cycle, as well as extend-ing the study of the carbon cycle to include socioeconomics as an interacting element.

These cross-disciplinary col-laborations will be vital in ensur-ing the global carbon cycle is accurately represented in our models of the greenhouse world.

Peter CoxHadley Centre for Climate Prediction and

Research,United Kingdom

E-mail: peter.cox@metoffi ce.com

Pierre FriedlingsteinLSCE,France

E-mail: pierre@lsce.sacaly.cea.fr

Peter RaynerCSIRO,

AustraliaE-mail: ray060@dar.csiro.au

References 1. Cox PM, Betts RA, Jones CD, Spall SA, Totterdell IJ. (2000). Accelera-

tion of global warming due to carbon cycle feedbacks in a coupled climate model. Nature 408,184-197.

2. Friedlingstein P, Bopp L, Ciais P, Dufrene J-L, Fairhead L, LeTreut H, Mon-fray P, Orr J. (2001). Positive feedback between future climate change and the carbon cycle. Geophys. Res. Let., 28, 1543-1546.

Reprinted with modifi cations from the joint BAHC/GEWEX newsletter, November 2001.

WebsitesC4MIP - http://www.atmos.berkeley.edu/c4mip/

GLASS - http://hydro.iis.u-tokyo.ac.jp/GLASS/

GCP - http://gaim.sr.unh.edu/cjp/GCP_FRAMEWORK.html

Other cross-disciplinary projects are also of vital importance to this endeavour. The Global Land-Atmosphere System Study (GLASS) is utilis-ing the well developed PILPS off-line methodology to com-pare and assess the latest generation of GCM land-sur-

face schemes which include carbon cycling (“PILPS-C1”). The “Global Carbon Project” (GCP) is a joint IGBP-WCRP-IHDP (International Human-Dimensions Programme) initiative which will provide valuable advances on the cou-pling between climate and the

Interactions between anthropogenic aerosols and the hydrological cycle

by U. Lohmann

The anthropogenic component of sulphate and carbonaceous aerosols has substantially increased the global mean aerosol burden from pre-industrial times to the present day and can infl uence the climate in different ways. The direct aerosol effect is caused by the absorption and scattering of solar radiation. Additionally, aerosols act as cloud condensation nuclei and thereby determine the initial cloud droplet number concen-tration, albedo, precipitation formation, and lifetime of warm clouds. For constant liquid water path, an enhancement in the cloud droplet number leads to an increase in cloud albedo (cloud albedo or fi rst indirect aerosol effect). As smaller cloud droplets have a lesser chance to collide and form precipitation size drops, the enhancement in cloud droplet number and decrease in cloud droplet size due to anthropogenic aerosols may cause a reduction in precipitation formation and increase in cloud lifetime (cloud lifetime or second indirect aerosol effect).

The cooling of the cloud albedo effect is estimated to be between 0 and -2 W m-2 in the global mean, but is still very uncertain [1]. The cloud lifetime effect is not a forcing because it involves interactions of aerosols with cloud droplets. It is estimated to be of comparable magnitude to the cloud albedo effect. This effect is even more uncertain because changes in the hydro-logical cycle associated with aerosols presently cannot be deduced from observational studies alone, but depend on a modelling component to fi ll in the gaps. It is these latter interac-tions between aerosols and the hydrological cycle that will be discussed below.

Anthropogenic aerosol emissions

Can anthropogenic aerosol

15

emissions in the Northern Hemisphere infl uence the pre-cipitation in the tropics and sub-tropics?

A mechanism by which anthropogenic aerosols could infl uence the Sahelian rainfall was proposed by Rotstayn and Lohmann [2] and Feichter et al. [3]. They used different atmospheric general circulation models (GCM), the CSIRO and ECHAM4 GCMs respectively, coupled to a mixed layer ocean to conduct equilibrium exper-iments in response to the anthropogenic aerosol loading. Whereas Rotstayn and Lohmann [2] included only sulphate aero-sols, Feichter et al. [3] con-sidered sulphate, dust, sea-salt and carbonaceous aerosols. In both simulations the greenhouse gas concentrations were kept at present day values. In the pre-industrial simula-tions, the fossil fuel emis-sions were set to zero and the biomass burning emis-sions were reduced to 0% or 10% of their present-day values. The CSIRO model only considers the cloud albedo and the cloud life-time effect by empirically relating the sulphate aerosol mass to the number of cloud droplets. In this approach sul-phate aerosols are used as a sur-rogate for all aerosols.

The ECHAM model con-siders the direct and the semi-direct aerosol effect in addition to both indirect aerosol effects. The semi-direct effect refers to absorption of solar radiation by black carbon (BC) which can lead to a heating of the air and can result in an evaporation of cloud droplets. Thus, the warm-ing caused by the semi-direct effect can partially offset the cooling due to the indirect aero-sol effect, as outlined in Lohm-ann and Feichter [4]. Here the

number of cloud droplets is obtained from a balance equa-tion. Cloud droplet nucleation is parameterised as a function of total aerosol number concen-tration, updraft velocity, and a shape parameter, which takes the aerosol composition and size distribution into account. The total number of aerosol par-ticles is obtained as the sum of marine sulphate aerosols pro-duced from dimethyl sulphide, hydrophylic organic and black carbon, submicron dust, and sea-salt aerosols. Anthropogenic sulphate aerosols only add mass to the pre-existing aerosols but do not form new particles.

The response due to the anthropogenic aerosol loading in both models was then obtained as the difference between the present-day and

the pre-industrial simulations. The surface temperature was reduced everywhere, caused by the different anthropogenic aerosol effects. As this cooling is largest in the Northern Hemi-sphere, it changes, for instance, the meridional gradient of the sea surface temperature in the Atlantic. In the model simula-tions, this strengthens the trade winds and reduces the strength of the African monsoon result-ing in drought conditions in the Sahelian region.

The strength of the African monsoon and the observed rain-fall amounts in the Sahelian region closely follow the trends in sulphur dioxide emissions.

“...increasing pollution in the Northern Hemisphere can have far reaching effects, such as contribut-ing to droughts in the Sahel region.”

The Sahelian precipitation decreased continuously from the 1950s through the 1980s but recovered in the 1990s. This coincides with reduced emis-sions of sulphur dioxide enforced by the Clean Air Act in North America in the 1980s and in Europe in the 1990s.

Rotstayn and Lohmann [2] compared the hemispheric dif-ference in cloud droplet effective

radius from the model to satellite estimates. The underlying idea is that the higher aerosol concentrations in the Northern Hemisphere caused by anthropogenic activity would lead to more but smaller cloud droplets so that the cloud droplet size distribution is characterised by a smaller effective radius.

Unfortunately, the two available satellite retrievals by Han et al. [5] and Kawamoto et al. [6] substantially differ in their esti-mates of the hemispheric effec-tive radius difference over the oceans. Whereas Han et al. [5] predict 0.9µm smaller droplets in the North Atlantic, Kawa-moto et al. [6] actually predict 0.1µm larger droplets over the North Atlantic as compared to the South Atlantic. The CSIRO models agree exactly with the earlier estimate by Han et al. [5].

The change in zonally aver-aged rainfall in response to the anthropogenic aerosol loading from the CSIRO model is shown in Figure 1 together with the

16

observed trend in precipitation from 1901 to 1998. Most striking is the southward shift in precipi-tation with a decrease in precipi-tation between the equator and 20˚N and an increase between 20˚S and the equator in both the model and the obser-vations. The increase in precipitation in the North-ern Hemisphere mid lat-itudes probably results from the increase in green-house gases and, therefore, cannot be captured in this simulation where green-house gas concentrations were kept constant. The ECHAM model gives sim-ilar results (not shown). Here the shift in precipita-tion is less pronounced because of the effect of including bio-mass burning aerosols that cool the tropical southern hemi-sphere and therefore reduce the meridional temperature gradi-ent in the Atlantic if compared to including only the effect of sulphate aerosols.

Analyses in more detail, in agreement with observations, show that both models simulate less precipitation over the Sahel zone in response to a weaker summer monsoon. In other words, the authors suggest that

the simultaneous increase in the abundance of atmospheric greenhouse gases and aerosol particles since World War II may have contributed to the observed drought in Western Africa via a change in the merid-ional temperature gradient. The increase in sulphate aerosols over the North Atlantic results

Figure 1 Zonally averaged trend in observed annual-mean precipitation over the period 1901-1998 [mm day-1 century-1] (dotted line) and zonally average difference in annual-mean precipitation between present-day and pre-indus-trial simulations with the CSIRO [mm day-1] (solid line) GCM. Points at which the observed trend is signifi cant at the 5% level are shown as asterisks.}

Reproduced from J. Climate [2]

Copyright America Meteorological Society 2002

primarily from fossil fuel use in North America and Europe. Control of sulphur emissions in the industrialised countries of the northern hemisphere might have been a signifi cant factor in the recovery from the drought

during the 1990s. If confi rmed, this hypothesis would provide a striking example of a tele-connection between anthro-pogenic perturbations in the industrialised regions of the northern mid-latitudes and cli-mate change in the subtropics.

Can anthropo-genic aerosols

infl uence mid-lati-tude precipitation?

Since natural ice nuclei are scarce, especially at small super-coolings, on the order of 1 ice nucleus in 1 million aerosol par-ticles, anthropogenic ice nuclei can potentially be a very impor-tant contributor to glaciation of supercooled clouds. However, the connection between aerosols and ice clouds is presently con-sidered to be too uncertain to even speculate on whether it would be a positive or negative radiative climate forcing [1].

Evidence for ice-forming activity of soot particles of vari-ous sizes as contact nuclei has recently been studied in a cloud chamber for temperatures rang-ing from -5˚C to -20˚C [7]. This study found that the fraction of soot particles forming ice crys-tals increased with decreasing temperature, increasing size of the aerosol particles and with the degree of oxidation of the soot particle surface. If soot was oxidised, the surface chemical groups could form hydrogen bonds with water molecules.

These fi ndings motivated Lohmann [8] to propose the hypothesis that anthropogenic

“Control of sulphur emis-sions in the industrialised countries of the northern hemisphere might have been a signifi cant factor in the recovery from the drought during the 1990s”

17

soot aerosols can infl uence the glaciation of clouds and with that modulate the indirect aero-sol effect as shown in Figure 2. If no ice nuclei are present, more aerosols lead to more cloud condensation nuclei (CCN), a higher cloud droplet number concentration (CDNC) and less precipitation. For a constant liquid water content, this will increase cloud albedo. In addi-tion, the reduction in precipi-tation prolongs the lifetime of clouds and the cloud fraction, which also increases the cloud albedo.

If, on the other hand, suffi -cient contact ice nuclei (IN) are present, more ice particles (IP) can be formed. This would lead to more frequent glaciation of supercooled clouds as the ice crystals grow rapidly at the expense of the droplets in a high ice supersaturated environment so that more precipitation is formed. As a consequence, the cloud fraction would decrease thus allowing more shortwave radiation to be absorbed in the Earth-atmosphere system.

Sensitivity studies with vary-ing amounts of soot acting as ice nuclei showed that if 1% to 10% of the hydrophilic black carbon acted as ice nuclei in addition to dust as a natural ice nuclei, then the precipitation is increased and cloud cover and liquid water path (LWP, the ver-tically integrated cloud liquid water amount) are decreased in mid-latitudes via the above mentioned mechanism, see Figure 3. Thus, more solar radia-tion can penetrate to the surface. This means, if a non-negligible fraction of soot aerosols acts as ice nuclei, the glaciation indirect aerosol effect could reverse or at least reduce the effect that anthropogenic aerosols have on the shortwave radiation at the top of the atmosphere.

Could anthropo-genic aerosols

change the global hydrological cycle?

Whether aerosols scatter or absorb solar radiation, the domi-nant effects of aerosols on the radiation balance at the surface is a reduction in shortwave radiation. This cooling of the surface temperature leads to smaller evaporation rates which, in equilibrium, are then bal-anced by lower precipitation rates. This can result in a weaker monsoon due to the cooler land surface temperatures as outlined above. This will reduce the latent and sensible heat transfer from the surface to the atmo-sphere. To investigate the impor-tance of this effect in a future climate Roeckner et al. [9] con-ducted a set of transient experi-

ment from 1860 to 2100 in which the ECHAM4 GCM was cou-pled to an oceanic general cir-culation model and included an interactive sulphur cycle. The fi rst experiment only included carbon dioxide and other well mixed greenhouse gases (GHG), the second included GHG and the direct effect of sulphate aero-sols, and the third included GHG plus tropospheric ozone and the direct and fi rst indirect aerosol effect, the effect of aerosols on cloud albedo, empirically estimated from the sulphate aerosol mass.

Roeckner et al. [9] concluded that the hydrological cycle will be weaker in the period 2030-50 as compared to the present-day climate when the direct and indirect effect of sulphate aero-sols and tropospheric ozone are included. In this scenario, pre-cipitation decreased by 0.4%

Figure 2. Schematic diagram of the warm indirect aerosol effect (solid arrows) and glaciation indirect aerosol effect (dotted arrows).

CDNC = cloud droplet number concentrationCCN = cloud condensation nucleiIP = ice particlesIN = ice nucleiCopyright America Geophysical Union

18

per degree increase in tempera-ture. In contrast, if only green-house gases are considered, then the precipitation increases by 0.7%K. The weaker hydrological cycle in the aerosol experiment is caused by the anomalous net radiative cooling at the Earth’s surface through aerosols. It is balanced by reduced turbulent transfer of both sensible and latent heat. It is interesting to note that the direct effect of sulphate aerosols alone is not able to decrease precipitation in the warmer climate but only reduces the increase of precipi-

tation in the warmer climate to 0.3%K.

ConclusionsWe are entering a new area of aerosol research by investigating the interactions between aero-sols and the hydrological cycle. Research in this area started with cloud seeding research, as summarised in the overview article by Bruintjes et al. [10]. Investigations in cloud seeding research are interested in satel-lite-based microphysical retriev-als that can be combined with in situ cloud sampling to monitor

the effects of natural and anthro-pogenic aerosol or hygroscopic seeding material on cloud drop-let size evolution, and the effects of ice-forming nuclei on ice-particle concentrations, both of which determine the effi ciency of precipitation production. The cloud seeding community, how-ever, is not interested in the cli-mate impact of anthropogenic aerosols or their effect on the global hydrological cycle, but only the infl uence of aerosols on precipitation on a local to regional scale. Still a knowledge exchange between the two research communities would be benefi cial.

As presented above, increas-ing pollution in the Northern Hemisphere can have far reach-ing effects, such as contributing to droughts in the Sahel region. Such an effect could lead to positive feedbacks as a decrease in precipitation could increase dust storms and biomass burning which in turn could decrease the precipitation even more via the cloud lifetime effect. Changes in meridional sea surface temperature gradient may have further teleconnection effects that we are currently not aware of. Longitudinal changes in temperature could result from strong biomass burning and could, for instance, infl uence the Walker circulation. This is an area that requires further research as only recently scien-tists started to investigate these effects.

In general, our knowledge about aerosol effects on clouds and the hydrological cycle is still very rudimentary. There-fore, clearly more research in terms of fi eld experiments, lab-oratory studies and modelling efforts is needed in order to understand and quantify the effect of anthropogenic aerosols on clouds and the hydrological cycle. This is especially impor-

Figure 3. Zonal annual mean changes between present-day and pre-indus-trial times for experiments with varying amounts of black carbon (BC) acting as ice nuclei: BC10% (solid line) BC1% (dot-dashed line) and BC0% (dotted line)

Copyright American Geophysical Union

19

Reprinted with modifi cations from the IGAC newsletter No 26 (April 2002)

References1. Ramaswamy V et al. (2001). In ‘Climate Change 2001: The Scientifi c

Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Chapter 6: Radiative Forcing of Climate Change, pp 349-416, Cambridge Univ. Press, New York

2. Rotstayn LD and Lohmann U. (2002). Tropical rainfall trends and the indi-rect aerosol effect. J. Climate, in press

3. Feichter JE, Lohmann U, Roeckner E and Brasseur GP. Did anthropo-genic aerosols contribute to the 1970-1990 Sahelian drought? Submitted to Nature, 2002

4. Lohmann U and Feichter J. (2001). Can the direct and semi-direct aero-sol effect compete with the indirect effect on a global scale? Geophys. Res. Lett. 28: 159-161

5. Han Q, Rossow WB and Lacis AA. (1994). Near-global survey of effec-tive droplet radii in liquid water clouds using {ISCCP} data. J. Climate 7: 465-497

6. Kawamoto K, Nakajima T and Nakajima TY. (2001). A global determina-tion of cloud microphysics with {AVHRR} remote sensing. J. Climate 14: 2054-2068

7. Gorbunov B, Baklanov A, Kakutkina N, Windsor HL, and Toumi R. (2001). Ice nucleation on soot particles. J. Aerosol Science 32: 199-215

8. Lohmann U. (2002). A glaciation indirect aerosol effect caused by soot aerosols. Geophys. Res. Lett. 29, in press.

9. Roeckner E, Bengtsson L, Feichter J, Lelieveld J and Rodhe H. (1999). Transient climate change simulations with a coupled atmosphere-ocean GCM including the tropospheric sulphur cycle. J. Climate 12: 3004-3032

10. Bruintjes RT. (1999). A review of cloud seeding experiments to enhance precipitation and some new prospects. Bulletin of the American Meteoro-logical Society 80: 805-820

11. Stocker TF et al. (2001). In ‘Climate Change 2001: The Scientifi c Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. Chapter 7: Physical climate processes and feedbacks, pp 417-470, Cambridge Univ. Press, New York

tant because cloud feedbacks in climate models still present one of the largest uncertainties. As shown in Stocker et al. [11] there is still no consensus on whether clouds provide a neg-ative or positive climate feed-back in response to a doubling of carbon dioxide. It is largely because of these uncertainties in cloud feedback that the uncer-tainty range of the increase in the global mean surface tem-perature in response to a dou-bling of carbon dioxide varies between 1.5 and 4.5 K.

Acknowledgements: Thanks to Hans Feichter for comments and suggestions, to Stockholm University for support and to IGAC for providing travel support to the IGAC Planning Meeting in Stockholm (27-30 January 2001).

Ulrike LohmannDepartment of Physics and Atmospheric

Science,Dalhousie University, Halifax,

CanadaE-mail: Ulrike.Lohmann@Dal.Ca

IGBP Science Series 1, 2, 3 and 4The IGBP Science Series is designed to make IGBP’s research output accessible to a wider range of audiences, in particular to the policy and resource management communities.

These visually rich reports present the most recent scientifi c understanding in major areas of Earth System Science.

To order copies send an e-mail to: sec@igbp.kva.se

Now Available

Integration

The Twenty-Three GAIM QuestionsThe course of global change research, and Earth System science in general, is determined by the scientifi c questions that challenge the scientifi c community. In 2001, in response to the evolving science, structure and results of IGBP, GAIM developed a set of such questions (see box). As well as challenging the community, they put the present body of IGBP research into context, and also highlight any gaps in our conceptual approach or research strategy.

These questions are not limited in scope to those that can be answered by individual research projects, programs, or even communities. Rather, they help to defi ne the overall context of global change science regardless of present ability to address the issues articulated therein. As part of its analysis role, GAIM is developing explanations of the meaning and implications of the questions, the state of the art as pertains to each, and a strategy for exploring each one. The latter is a critical aspect, and due to the breadth of the questions, will range from specifi c scientifi c activities, to the exploration of dialogue with communities

This article is the fi rst in our new regular feature on integration. One of the most prominent characteristics of IGBP II is the increasing emphasis on the integration of the subcomponents of the Earth System to build a more complete picture of the functioning of the global environment. Such integration can occur in various ways - through inter-core project collaboration, through regional studies, through the activities of GAIM, and by the joint research of IGBP and its partner global change programmes in the ‘Earth System Science Partnership’.

In this issue we feature the 23 GAIM questions, a set of overarching questions designed to challenge the entire global change research community, and society more generally, for decades into the future. Following a general introduction to the whole set of

questions, we focus more strongly on of them – no. 14: “What are the most appropriate methodologies for integrating natural-science and social-science knowledge?” We hope to focus on other questions in future editions of the newsletter.

20

Analytic Questions:1. What are the vital organs of the ecosphere in

view of operation and evolution?

2. What are the major dynamical patterns, telecon-nections and feedback loops in the planetary machinery?

3. What are the critical elements (thresholds, bottle-necks, switches) in the Earth System?

4. What are the characteristic regimes and time-scales of natural planetary variability?

5. What are the anthropogenic disturbance regimes and teleperturbations that matter at the Earth-System level?

6. Which are the vital ecosphere organs and criti-cal planetary elements that can actually be trans-formed by human action?

7. Which are the most vulnerable regions under global change?

8. How are abrupt and extreme events processed through nature-society interactions?

Operational Questions:9. What are the principles for constructing “macro-

scopes”, i.e., representations of the Earth System that aggregate away the details while retaining all systems-order items?

10. What levels of complexity and resolution have to be achieved in Earth System modelling?

11. Is it possible to describe the Earth System as a composition of weakly coupled organs and regions, and to reconstruct the planetary machin-ery from these parts?

12. Is there a consistent global strategy for gener-ating, processing and integrating relevant Earth System data sets?

13. What are the best techniques for analysing and possibly predicting irregular events?

14. What are the most appropriate methodologies for integrating natural-science and social-science knowledge?

Normative Questions:15. What are the general criteria and principles for

distinguishing non-sustainable and sustainable futures?

16. What is the carrying capacity of the Earth as determined by humanitarian standards?

17. What are the accessible but intolerable domains in the co-evolution space of nature and human-ity?

18. What kind of nature do modern societies want?

19. What are the equity principles that should govern global environmental management?

Strategic Questions:20. What is the optimal mix of adaptation and mitiga-

tion measures to respond to global change?

21. What is the optimal decomposition of the plan-etary surface into nature reserves and managed areas?

22. What are the options and caveats for technologi-cal fi xes like geoengineering and genetic modifi -cation?

23. What is the structure of an effective and effi cient system of global environment and development institutions?

Box: The GAIM Questions

far beyond IGBP and the ‘Earth System Science Partnership’.

The GAIM questions should, in fact, anticipate the advent of a unifi ed Earth System Science and therefore encompass the natural and socioeconomic dimensions in a balanced way. This accounts for “hor-izontal integration” across the disciplines, but “vertical integration” across the layers of the problem-solving process is no less important.

John SchellnhuberPotsdam Institute for Climate Impact Research (PIK)

PO Box 60 12 03,D-14412 Potsdam,

GermanyE-mail:john@pik-potsdam.de

Dork SahagianGAIM Task Force Offi ce,

Institute for the Study of Earth, Oceans & Space (EOS),University of New Hampshire,Morse Hall, 39 College Road,

Durham, NH 03824-3525,USA

E-mail: gaim@unh.edu

21

Human-Environment Interactions:Methods and TheoryThe new IGBP embraces the challenge of a more inte-grated approach to analysis and synthesis of knowl-edge about the Earth System. This System is a close set of interrelationships between people and nature, and the greatest intellectual challenge is to make the ‘Earth System Science Partnership’ (ESSP) work so that these interrelationships can be better understood. We will need workable analytical and synthetic meth-ods, and theories of the interrelationships, that will help policy and decision makers better understand the world in which they are operating.

The integrative research required by the ESSP is being pursued in many parts of the Global Change Programmes, and the challenge of integration within the natural sciences is gradually being met. But by far the greatest challenge is bridging the disciplinary divide between natural science, social science, and the humanities to develop generalisations (theory) about human environment interactions.

A small group spanning the interests of IGBP and IHDP has formed to tackle some of the methodologi-cal and theoretical issues that all partners in the ESSP will face. Our role is not to displace work already going on in parts of the Partnership, but to pool experi-ence and knowledge, refl ect on successes and fail-ures, and by publishing our ideas and conclusions, aid the development of this crucially important fi eld of research.

The small group met in Oslo in 2001, and so is called The Oslo Group (TOG). The acronym is also the Norwegian word for train, and the group sees itself as setting out on an important and diffi cult journey.

Sustainability problems demand integrated knowledge about natural systems, history, human society, and human behaviour. The human-environment system involves large numbers of interacting agents and com-ponents (both human and non-human), is adaptive and self-organising, and is dynamic in rich and often

surprising ways. This system is therefore an iconic complex system.

There are already in existence methods for studying this system, including system dynamics, the narrative methods of environmental historians, environmental and ecological economics, human ecology, policy and institutional analysis. These are also generic concepts such as risk and resilience that pervade both the human and non-human worlds. These methods need further development, and TOG intends to undertake some of this development. TOG will be most effective if it takes a global change view, and seeks to comple-ment other relevant activities (e.g. IGBP’s Non-linear Group, the Resilience Alliance, and various national efforts).

TOG has undertaken to answer one of the GAIM questions:

What are the most appropriate methods for integrating natural science, social science, and humanities knowledge? (No. 14)

This question has been modifi ed from the original to include the humanities, because most decisions about the environment include human values and beliefs, and we also wish to highlight the importance of envi-ronmental history.

To this question we have added:

What are the current theories of human-environ-ment interactions that help identify sustainable futures?

Our initial discussions in Oslo identifi ed two broad themes within the second question that we wish to tackle, namely the identifi cation of the characteristics of resilient (durable) systems, and the dynamical rela-tionships between knowledge production, policy for-mulation, and decision making.

TOG currently consists of Carol Crumley, Eric Lambin, Nordin Hassan, Claudia Pahl-Wostl, Barry Newell, Arild Underdal and Bob Wasson. We have begun to write an overview paper for wide distribution within

Some of the 23 questions are quite specifi c and apply only to certain fi elds within Earth System Science. Others are very broad, and can be seen either as overarching questions or interpreted with different angles by different fi elds. There will many ways to tackle these questions. At the recent IGBP SC meeting in Stockholm (19-22 February 2002), two main approaches were proposed. Firstly, each core project should adopt the relevant questions into

more focused questions appropriate for their science. Secondly, each year a few of the GAIM questions will be addressed by small task teams, who will meet and possibly produce a paper with a state-of-the-art review of the knowledge existing to begin answering the question. A newly formed task-team, the Oslo Group, has already begun this process by taking on question 14. The following section describes their approach.

22

the ESSP and also plan to work our way through many of the issues identifi ed in Oslo over the next few years. We would welcome ideas, material and critical comments so that our work is connected to the rest of the ESSP. TOG will operate as a complex, adaptive system!

Bob WassonCentre for Resource and

Environmental StudiesInst. of Advanced Studies

School of Res. Management &Env. Science

Australian National UniversityCanberra ACT 0200

AustraliaE-mail: Robert.Wasson@anu.edu.au

Arild UnderdalDepartment of Political Science

University of Oslo0317 Oslo

Norway E-mail: arild.underdal@stv.uio.no

Discussion Forum

Collaboration between natural and social scientists will only be successful if programmes and projects are initiated and planned by integrated teams from both disciplines, and supported by funding agencies who have a high-level commitment to interdisciplinary research. This was one of the conclusions drawn by a European Science Foundation (ESF) Forward Look meeting, held in Stockholm between 30th January and 1st February 2002. The meeting looked at the management and funding of global change research in Europe. This brief article is a personal report on some of the conclusions.

As the policy and societal relevance of the IGBP research agenda increases, so does the need to col-laborate with social scientists, such as those of the International Human Dimensions Programme (IHDP). People, of course, live on the land surface, so it is in land surface science where this need to collaborate is most urgent. Ten years ago social science was totally absent from IGBP land surface research, such as the HAPEX-Sahel experiment held in 1992. Yet, recent use of the HAPEX-Sahel data to model the climatic effects of land cover change in the Sahel revealed the need for factual, historical land cover change data, and estimates of future land cover based on predicted demographic and other social changes. A resulting collaboration between BAHC and LUCC scientists has now produced the fi rst realistic estimate of the climatic effects of actual land cover change in the region [1].

Similarly in South America the current Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA) was designed with no socioeconomic compo-nent. This is now being added and studies such as those on the causes of deforestation and the sustain-

Natural Sciences, Social Sciences: Integration or Summation?

Interdisciplinary research is central to the rapidly developing agenda of Phase II of IGBP, and collaboration with the International Human Dimen-sions Programme is essential. But interdisciplinary is not the same as multidisciplinary – integration is not the same as summation! To achieve this integration will require a fl exible, open-minded approach by both the natural and social scientists, and their funding agencies.

ability of deforested land are being added to the studies of the physical and biological functioning of the Amazon basin. However, making these additions at this late stage is diffi cult - it would have been

Box. Natural and Social Science Collaborations

Failed collaborations are likely to have:� No shared concepts

� Questions formulated by one side

� Problems with semantics

� Lack of commitment

� Misconception of roles and place

� Diffi culty in attracting scientists

� Poor communication and physical separation

Successful collaborations are likely to have:

� Shared concepts & language

� Excellency in own fi eld

� Joint proposal development

� Sub-projects to allow individuals to succeed in their own fi eld

� Intellectual respectability

� Long term commitment

� Good communication and personal contact

24

much more easily done as part of the initial design process fi ve years ago. If it had been, a very different experimental design might well have emerged.

ManagementThe social and natural sciences have different cultures and to be successful collaboration requires each to be aware of these differences. A working group at the ESF Forward Look meeting discussed these dif-ferences starting with the lists in the Box, which were drawn up by Professor Leen Hordijk of Wageningen University. Clearly, without an open-minded attitude and a willingness to learn on both sides it will be easier to fail than to succeed.

The reasons for success in the Box are really no more than the basic rules of team management: shared project design and shared decision making leads to shared project ownership, motivation and commit-ment. The meeting recognised that the key to success is to build an integrated team from the start. This is the approach advocated by the new UNESCO/WMO HELP (Hydrology for the Environment, Life and Policy) initiative. This programme plans to establish a global network of catchments as a framework for natural and social scientists to work together with environmental managers to research locally defi ned issues [2].

Lastly, building on already established strong areas of collaboration to create a ”fl agship” projects was identi-fi ed as a sensible starting point. Land use and land cover change, vulnerability and food provision were

Food provision was identifi ed as one area where good collaboration between natural and social scientists is essential. Hydrologists and economists working in Zim-babwe found that when community gardens are organ-ised around productive wells that provide more water than is needed for basic sanitation and subsistence, surplus vegetables are sold. This provides cash for pump maintenance and produces a positive spiral of economic growth which is sustainable. Good siting and design of wells combined with community ownership and management is the key to success [3].

(photos by C Batchelor)

seen as good examples where existing collaboration could be expanded.

Institutional obstaclesResearch funding agencies are generally not well structured for dealing with interdisciplinary projects. In most cases national funding is channelled through different agencies for the natural and social sciences. Even where it is not, there will almost certainly be different committees responsible for funding the research from the various disciplines. These com-mittees may well have terms of reference which effectively prevent them from funding interdisciplinary proposals.

Rather than fi ght this system from below, what is needed is a high-level commitment to interdisciplinary research. When this exists the situation can be radi-cally transformed. A good example is the United King-dom’s Tyndall Centre. This centre is funded by a large grant jointly provided by the three UK research councils responsible for funding the environmental, physical and social sciences (NERC, EPSRC and ESRC). The Tyndall Centre is researching the impacts of climate change – working at the interface between climate research and research on policy.

In the longer term there is a need to expose young scientists to the whole spectrum of the natural and

25

References1. Taylor CM, Lambin EF, Stephenne N, Harding RJ and Essery

R. (2002). The infl uence of land use change on climate in the Sahel. Submitted to J. Climate

2. UNESCO. (2001). The design and implementation strategy of the HELP initiative. IHP-V, Technical Document in Hydrology, 44, UNESCO, Paris

3. Lovell C. (2000). Productive Water Points in Dryland Areas: Guidelines on integrated planning for rural water supply. ITDG Publishing, London.

social science aspects of global change research. Both generalists and specialists are needed, but whatever the subject of their thesis, newly qualifi ed PhDs should be comfortable working in an interdisci-plinary environment. Graduate summer schools on global change research are one way of starting this process.

Summing upSumming up at the end of the meeting Dr John Marks, Director for Earth and Life Sciences at The Netherlands’ funding agency NWO, said “Breaking down the intellectual barriers to collaboration is ulti-mately up to the scientists themselves, but there is a clear role for the ESF to mobilise the commitment of the European funding agencies to the new global change agenda, and to ensure that artifi cal adminis-

trative barriers do not prevent the necessary interdis-ciplinary research from being funded”.

John GashCentre for Ecology and Hydrology

Wallingford OX10 8BB,UK

E-mail: jhg@ceh.ac.uk

Are you interested inZooplankton?Climate?Fisheries?THEN DON’T MISS THE MOST EXCITING GLOBEC EVENT YET!

GLOBEC 2nd Open Science Meeting15-18 October 2002Come to the beautiful coastal city of Qingdao in P. R. China for the GLOBEC 2nd Open Science Meeting, 15-18 October 2002. Registration is now open online at www.globec.org/osm/. Submit your abstracts without delay to improve your chances of getting an oral presentation slot!

The GLOBEC OSM promises to be one of the most exciting events of the year with scientists from around the world gathering to exchange ideas, make new contacts, set up collaborations and discuss ideas for new synthesis publications.

www.globec.org/osm/

4 days of world class science!

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Registration deadline: 1st August 2002

Abstract submission deadline: 1st July 2002

IGBP is in a transition phase. New projects are under develop-ment, both within IGBP and as joint projects with our three partner programmes (IHDP, WCRP and DIVERSITAS). Changes are also

occurring this year in the composition of the IGBP Scientifi c Committee, and this extends right through to the Chair of the organisation.

Scientifi c Committee At the end of 2001, Isao Koike (Treasurer), Bert Bolin, Wolfgang Cramer and Peter Tyson all rotated off; we thank them all for their invaluable contribu-tion to IGBP during their terms of offi ce. This of course means some new faces on the SC:

Takashi Kohyama is a professor at Hokkaido University, Japan. His interest is the architectural dynamics of forest ecosystems and tree species coexistence. Focal sites have been subalpine coniferous forests in central

Musical ChairsOn 1 January 2002 Professor Guy Brasseur became the Chair of the SC-IGBP, succeeding Professor Berrien Moore. Guy has a long history with IGBP, starting with membership on the IGAC Scientifi c Steering Committee in the early 1990s, followed by his

chairmanship of IGAC from the mid-90s. He has played an especially strong role in the IGAC Integration & Synthesis project, which has produced a landmark state-of-the science report in atmospheric chemistry. In addition to his IGAC duties, he has also been a member of the GAIM Task Force for the past three years.

One of Guy’s unique strengths is his in-depth knowledge of global change science on both sides of the Atlantic, and in many other parts of the world. For many years he worked at the National Center for Atmospheric Research (NCAR) in Boul-der, Colorado, USA, where he was head of the Atmospheric Chemistry Division. Two years ago he returned to Europe, becoming Director of the Max Planck Institute for Meteorology in Hamburg, Germany. In addition, he also has a background in politics, having interrupted his scientifi c career earlier to become a member of the Belgian

Parliament. This experience will no doubt serve Guy well as the whole fi eld of global change

science becomes increasing important in the political sphere of life.

While welcoming Guy to the Chairmanship, the IGBP community also sincerely thanks Berrien for his outstanding leadership during this challenging period for the programme, and for his tireless efforts in

promoting global change science around the world. Although Berrien has offi cially stepped down as Chair, he will continue on the SC-IGBP through 2002 and will continue to play an active part in the

programme’s future for many years to come.

Almut Arneth will be assisting Guy Brasseur with the daily tasks of chairing IGBP. Her research at Landcare Research in Lincoln (New Zealand) and the Max Planck Institutes for Biogeochemistry and Meteorology (Germany) has

focused on terrestrial ecosystem carbon and water fl uxes (i.e., long-term responses to climate change, and atmospheric CO2 concentration, impacts

Japan, warm-temperate rain forests in southern Japan, and tropical rain forests in Sumatra and Kalimantan. He has been carrying out fi eldwork such as permanent plot monitoring, tree dimension analysis and theoretical modelling of forest dynamics at various levels, from tree architecture to forest landscape. He is Chairman of the Steering

Committee of the GCTE project “Global Change Impacts on Terrestrial Ecosystems in Monsoon Asia” (TEMA).

Michel Loreau is a professor at Pierre and Marie Curie University in Paris. He joins the IGBP SC by virtue of

People and events

27

being the chairman of the Scientifi c Committee of DIVERSITAS, but is already familiar to the IGBP community through his work with GCTE. He is currently an editor of four of the top ecological journals, the winner of several scientifi c prizes, and the author of over 150 scientifi c publications in the fi elds of theoretical ecology, community ecology, ecosystem ecology, population ecology and evolutionary ecology. His current research aims to make a synthesis between the widely separated fi elds of ecosystem functioning and community organisation and diversity.

Prof Mary Scholes is currently an associate pro-fessor in the Department of Animal, Plant and Environmental Sciences at the University of the Witwatersrand, South Africa. She has spent time at North Carolina State University working on the sustainability of low-input agriculture in the Peru-vian Amazon, and also at the National Center for Atmospheric Research and Colorado State Univer-sity, USA. Her research activities focus on soil fer-tility and biogeochemistry in savannas, forests and croplands. She is active in a number of regional and international advisory committees to do with soil fertility and tropical agriculture. Her interests in nitrogen cycling have resulted in her being elected to two international science steering committees focusing on trace gas emissions; this involves col-laborative research with a number of overseas institutes.

Peter Liss was featured in NL 48 (Dec 2001) as the new chair of SOLAS: he also joins the IGBP SC.

Seth Krishnaswami is already known to us as an SC member, but has a new role as Treasurer.

Two other people join SC members due to their new positions as co-Chairs of START:

Sulochana Gadgil is a professor at the Centre for Atmospheric and Oceanic Sciences, Indian Insti-tute of Science, Bangalore. She actively partic-ipated in the Joint Scientifi c Committee of the WCRP and the START SSC, and has played a major role in the preparation and execution of the science plan of the Indian Climate Research Pro-gramme. She has worked on monsoon dynamics and variability and its links with agriculture and has been involved in CLIMAG since its inception.

Graeme Pearman is Chief of CSIRO Atmospheric Research, Australia and is also Chair of the Sci-entifi c Planning Group of the Asia-Pacifi c Network. He was a participant in the 1990 IGBP Bellagio workshop that led to the creation of START and is a past chair of the START committee for SE Asia (SARCS). His research interests focus on the fi eld of atmospheric composition and, in particular, the global carbon cycle.

Joint Project Chairs

Global Carbon Project Co-ChairsRobert Dickinson is an atmospheric scientist with the School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, having been educated at Harvard and MIT. He will soon serve as President of the American Geophysical Union until

2004, and is already Chair of the Atmospheric and Hydrospheric Sciences Section of the American Association for the Advancement of Science (2001-2002), a member of the American Meteorological Society and the Climate System Modeling NCAR Scientifi c Steering Committee (1995-2002); and a Co-Chair for CLIVAR (2001-2002). In 2001, he served on the National Research Council Committee on the Science of Climate Change.

Michael Raupach is presently a Chief Research Scientist in CSIRO Land and Water, Canberra, Australia His major research interests are:

• Biosphere-a t m o s p h e r e interactions: the fl ows and stores of energy,

water and carbon in landscapes, at local, continental and global scales

• Wind fl ows and the spread of windborne materials in the lower atmosphere, espe-cially over the Earth’s surface

• Soil erosion by wind, including studies of the windborne transport of solid particles, erosion control by vegetation, and wind erosion and long-term agricultural sustainability.

28

Oran R. Young is Profes-sor of Environmental Stud-ies and Director of both the Institute of Arctic Studies and the Institute on International Environmen-tal Governance at Dart-mouth College in the United States. He is also Professor II of Political Science at the University of

Tromsø in Norway. He chairs the Scientifi c Steering Committee of the international project on the Institutional Dimensions of Global Environmental Change (IDGEC) and is chairman of the Board of Governors of the University of the Arctic. The most recent of his many books is ‘The Institutional Dimensions of Environmental Change’ (2002).

GECAFS (Global Environmental Change and Food Systems)

Peter Gregory (GECAFS Chair) is Professor of Soil Science at the University of Reading, UK, where he has also held a number of senior positions. Over the last 20 years he been working in the UK and Austra-lia on the microclimatology of tropical crops, plant/soil

interactions, root growth and the uptake of water and nutrients by crops, and the chemical and physical limitations imposed by soils on crop production. His current research interests include the development of non-invasive techniques for imaging roots growing in soil, the chemical and physical properties of the mucilage produced by roots, modelling water and nutrient uptake by plant root systems, and developing sustainable systems of crop production.

Michael Brklacich (GECAFS Vice Chair) is an Associate Professor in the Department of Geog-raphy and Environmental Studies at Carleton Uni-versity, Canada. His interests lie in interdisciplinary approaches for assessing relationships between human use and impacts on environmental and nat-ural resources, and in the application of science to public policy. Over the past few years, he has focused on issues relating to agricultural adaptation to global change and food security. This newer work relies heavily on participatory research methods and on the integration of quantitative and qualitative research methods. He has been actively involved in the development of the Global Environmental Change and Human Security project, a core project within the International Human Dimensions Program on Global Environmental Change.

Transition Team Leaders for IGBP Phase II

AtmosphereTimothy Bates is currently a Supervisory Research Chemist at NOAA’s Pacifi c Marine Environmental Laboratory in Seattle, Washington, but also holds posts at the Department of Atmospheric Sciences and the Joint Institute for the Study of the Atmo-sphere and Ocean (JISAO), both at the University of Washington. His research has focused on marine atmospheric chemistry including the air-sea exchange of trace gases, the biogeochemical sul-phur cycle, and the chemical, physical and radia-tive properties of atmospheric aerosols. During the past eight years, he has been a coordinator of IGAC’s three Aerosol Characterization Experiments (ACE). He is currently a member of the Commis-sion on Atmospheric Chemistry and Global Pollu-tion (CACGP), and a member of the US interagency steering committee developing a National Aerosol-Climate Interactions Program.

Mary Scholes (see SC section on page 28)

LandLisa Graumlich is a professor at Montana State University (Department of Land Resources & Envi-

ronmental Sciences), where she is also the Director of the Mountain Research Center. Her interests are the interaction of climatic variation at multiple scales, ecological processes, and land-use and social factors in governing change in mountain regions.

Sandra Lavorel’s research interests focus on the dynamics of plant diversity in landscapes, especially in relation to natural and land use disturbances. She has been involved with several international comparative studies, and has coordinated research on global change effects on landscape structure and function. Since 1994 she has been a Research Scientist with CNRS in France, but has close connections with the Research School of Biological Sciences, Australian National University in Australia, where she worked from 1991-94. In 1997 she joined GCTE’s SSC, and has since become interested in integrating approaches to land use change research.

Emilio Moran is an expert in the fi eld of environmental anthropology, tropical ecol-ogy, and the human dimen-sions of global environmental change. He has contributed to the development of theory in cultural ecology and ecosys-tem ecology and has served

29

IGBP and Related Global Change MeetingsFor a more extensive meetings list please see our web site at www.igbp.kva.se

GCTE: From Transient to Steady State Response of Ecosystems to CO2-Enrichment and Global Warming28 April-1 May, Durham, New Hampshire, USAContact: Diane Pataki, pataki@biology.utah.edu

Workshop on Building Adaptive Capacity to Environmental Change in Southeast AsiaTBA, April, Chiang Mai, Thailand (tentative)Contact: Louis Lebel, llebel@loxinfo.co.th

IGBP/SCOR: Ocean Biogeochemistry and Ecosystems Transition Team Planning Meeting23-26 April, Potomac, Maryland, USAContact: Ed Urban, scor@jhu.edu

IGBP: Water Joint Project Meeting with Core Proj-ect Representatives8-10 May, Paris, FranceContact: Holger Hoff, hhoff@pik-potsdam.de

GLOBEC: SPACC Executive Committee Meeting11-12 May, Dartington, UKContact: GLOBEC IPO, globec@pml.ac.uk

as Leader of Focus 1 of LUCC since 1999. His major fi eld research has focused on land use change in the Amazon Basin, a topic he has fol-lowed for more than 30 years. He has been Director of the Anthropological Center for Training and Research on Global Environmental Change since 1992 and Co-Director of the Center for the Study of Institutions, Population and Environmental Change since 1996. He is a member of the National Academy of Sciences’ Committee on the Human Dimensions of Global Change, the Board of the National Museum of Natural History at the Smithsonian, and of the Scientifi c Steering Committee of the US Carbon Cycle Science Program.

Dennis Ojima is a senior research scientist at the Natural Resource Ecology Laboratory and an Assis-tant Professor at Colorado State University. He has served on a number of international and national committees dealing with ecosystem science, and was contributing author to several chapters of the 1995 Intergovernmental Panel on Climate Change. From 1988 to 1990, he was a Programme Offi cer with IGBP and was subsequently involved with LUCC. Dr. Ojima’s research activities address ecological issues related to global and regional land use and climate changes on ecosystem dynamics; studies of the interaction between terrestrial ecosystems and the atmosphere; the impact of changes in land management on trace gas exchange; and

the development of a global ecosystem model. Specifi cally his research is aimed at developing a better understanding of factors affecting ecological integrity and sustainable resource use.

Land-AtmospherePavel Kabat is already well known to the IGBP community through his work with BAHC, and as a member of the SC. His co-leader for Land-Atmo-sphere project is still to be decided.

Ocean Biogeochemistry and Ecosystem ActivityJulie Hall is a biological oceanographer from the National Institute of Water and Atmosphere in New Zealand. Her research is focused on the structure and dynamics of the microbial food web in both coastal and open ocean systems. Julie has been involved in the JGOFS programme both in New Zealand and internationally and was one of the team of scientists who conducted the fi rst iron addition experiment in the Southern Ocean. She has been a member of the JGOFS SSC and has also Co-Chaired the JGOFS/LOICZ Continental Margins task team. Julie is also involved in the development of the Global Ocean Observing System (GOOS) as Vice Chair of the GOOS SC and is also a member of the team developing the strategic and implementation plan for Coastal GOOS.

New faces at the IGBP SecretariatLast but not least, we have two new people at the Secretariat. Angelina Sanderson will be working on the IGBP Synthesis volume ‘Earth System Overview’ until the end of 2002. She has an Honours degree in Human Biology from Stanford University,

and her interests are in small-scale agricultural development.

Petra Nilsson will be helping John Bellamy with IGBP graphic design duties until the end of May.

A warm welcome to everyone in their new roles within IGBP!

30

GCTE: GCTE Focus 1 Workshop: Biological con-trols on the stable isotope composition of atmo-spheric carbon dioxide, methane and nitrous oxide: processes and applications12-14 May, Banff, CanadaContact: Diane Pataki, pataki@biology.utah.edu

GLOBEC: GLOBEC Executive Committee Meeting13-14 May, Dartington, UKContact: GLOBEC IPO, globec@pml.ac.uk

State of the Planet 2002: A Conference Exploring Science and Sustainability13-14 May, New York, USAContact: http://www.earth.columbia.edu/sop2002/aboutsop.html

16th Global Precipitation Climatology Project - Working Group on Data Management meeting13-17 May, Tokyo, JapanContact: GEWEX Project Offi ce, gewex@cais.com

PAGES: PAGES Scientifi c Steering Committee14-15 May, Moscow, RussiaContact: PAGES IPO, pages@pages.unibe.ch

PAGES: High Latitude Paleoenvironments16-17 May, Moscow, RussiaContact: Olga Solomina: solomina@gol.ruIsabelle Larocque: larocque@pages.unibe.chhttp://www.pages.unibe.ch/

Future of Glaciosphere in Changing Climate18-20 May, Pushchino, RussiaContact: igras@igras.geonet.ru or geograph@online.ru

ObituaryJames Ellis, an ecosystem scientist at the Natural Resource Ecology Laboratory of Colorado State University, died in an avalanche in west-ern Colorado on March 14, 2002. The world is diminished by his loss.

Dr. Ellis’ preeminent work on understanding the interplay between people and natural processes in arid ecosystems set a global standard for novel research spanning scientifi c disciplines. Jim focused much of his research on the role of climate variability in affecting ecosystem dynamics and human response to these dynamics in semi-arid eco-systems. He applied integrated, interdisciplinary approaches to under-standing pastoral ecosystem ecology throughout the world - in Africa, the Middle East, Asia, and North America. His work exerted broad impacts on contemporary science, but more, played a fundamental role in supporting wise management and policy in the developing world. Particularly notable was his extensive research on the ecology of pas-toralism in the Turkana District of Kenya during the 1980s, studies sup-ported by three major grants from the Ecosystem Studies Program and the Anthropology Program of the National Science Foundation. This project produced over 200 scientifi c publications. It was the fi rst exam-ple of a major research project integrating social and ecosystem sci-ence, an example that has been frequently imitated.

Dr. Ellis was a systems ecologist in the classical sense - his greatest strength was his ability to conceptualise large, complex scientifi c prob-lems as whole systems, to sketch the interactions among their signifi cant components, and to develop ways to understand their dynamics. In this way, he contributed much to global change science and was a key player in many research activities that became components of IGBP core projects. Dr Ellis was an outstanding example of the world-class scientists who so willingly contribute their time and expertise to international, collaborative research, and who form the backbone of IGBP’s networks around the world. His passing is a loss to all of us who value the sharing of scientifi c excellence across national and cul-tural boundaries towards a common vision of a better world.

He is survived by his wife and longstanding scientifi c colleague, Dr. Kathleen Galvin, and four sons, Gregory, Eric, Ian, and Stefan. The IGBP community sends its condolences to them.

31

GCSS-ARM Workshop on the Representation of Cloud Systems in Large-Scale Models20-24 May, Alberta, CanadaContact: GEWEX Project Offi ce, gewex@cais.com

GCTE: GEGC-II/GCTE Soil Erosion Network co-sponsored Meeting22-25 May, Chengdu, ChinaContact: Dr Yong Li, yongli32@hotmail

PAGES: The Northern Environment, 36th Congress Canadian Meteorological and Oceanographic Society22-25 May, Rimouski, Quebec, CanadaContact: larocque@pages.unibe.ch

GCTE: GCTE-SEN co-sponsored meeting. “Soil Erosion and Land Use Change”26-31 May, Chengdu, ChinaContact: http://www.wscc.org.cn/isco2002/index.htm

Holocene Environmental Change in the Great Lakes Region28 May-1 June, Toronto, CanadaContact: Matthew Peros: matthew.peros@utoronto.caSarah Finkelstein: sarah.fi nkelstein@utoronto.ca

LOICZ: Synthesis and Futures Meeting and Scien-tifi c Steering Committee Meeting27 May-2 June, Miami, FloridaContact: loicz@nioz.nl

Global Change Programmes. Chairs and Directors Meeting31 May-2 June, Bonn, GermanyContact: IHDP Secretariat, ihdp@uni-bonn.de

IHDP, START: 3rd IHDP/START bi-annual Workshop on Human Dimensions of Urbanisation and the Transition to Sustainability3-14 June, Bonn, GermanyContact: Maarit Thiem, thiem.ihdp@uni-bonn.dehttp://www.ihdp.org

START: AIACC Vulnerability and Adaptation Assessment Methods Training Course3-14 June, Treiste, ItalyContact: Sara Beresford, sberesford@agu.org

SOLAS: SOLAS Implementation Strategy Meeting10-14 June, Amsterdam, The NetherlandsContact: Peter Liss, p.liss@uea.ac.uk

GLOBEC: ICES Symposium on ‘Acoustics in Fisheries and Aquatic Ecology’10-14 June, Montpellier, FranceContact: François Gerlotto, gerlotto@orstom.fr or Jacques Massé, jacques.masse@ifremer.fr

GCTE: GCTE Focus 1/NCEAS 2nd working group meeting: Progressive nitrogen limitation of plant and ecosystem responses to elevated CO218-21 June, Santa Barbara, CA, USAContact: Diane Pataki, pataki@biology.utah.edu

5th International Integration of Icecore, Marine + Terrestrial Records (INTIMATE) workshop22-28 June, Tromso, NorwayContact: Wim Hoek: w.hoek@geog.uu.nlhttp://www.geog.uu.nl/fg/INTIMATE

Global Ocean Productivity and the Fluxes of Carbon and Nutrients: Combining Observations and Models24-27 June, Ispra, ItalyContact: Reiner Schlitzer, rschlitzer@awi-bremerhaven.dePatrick Monfray, monfray@cea.fr

GLOBEC: Focus 4 WG Meeting: ‘Global Changes in Marine Ecosystems and Coastal Communities: Who done it?’26-28 June, Sidney, CanadaContact: Ian Perry, perryi@pac.dfo-mpo.gc.ca or GLOBEC IPO, globec@pml.ac.uk

START: START Pan-Africa Regional Committee meeting in conjunction with the meeting of the African Ministers of the Environment (AMCEN)29-30 June, Kampala, UgandaContact: Eric Odada, eodada@uonbi.ac.ke

2nd LBA Science Conference7-10 July, Manaus, BrazilContact: LBA Central Offi ce, yara@cptec.inpe.br

START: START/IRI/Packard Advanced Training Institute on Climatic Variability and Food Security8-26 July, Palisades, NY, USAContact: James Hansen, jhansen@iri.columbia.edu

Quaternary Climatic Changes and Environmental Crises in the Mediterranean region15-18 July, Madrid, SpainContact: Ana Vadeolmillos Rodriguez, climatic.changes@uah.eshttp://www2.uah.es/qchange2002

GCTE: ICAR5/GCTE-SEN Wind Erosion and Aeolin Processes Conference22-25 July, Texas, USAContact: John Ingram, jsii@ceh.ac.uk

Symposium on Biosphere-Atmosphere Interactions at the VIII International Congress of Ecology (INTECOL)11-19 August, Seoul, KoreaContact: Wonsik Kim, wonsik-kim@yonsei.ac.krhttp://www.seoulintecol.org/

32

Hydrology for the Environment, Life + Policy Symposium19-22 August,Stockholm, SwedenContact: Jim Wallace

World Summit on Sustainable Development26 August-4 September, Johannesburg, South AfricaContact: http://www.johannesburgsummit.org

Enviromental Catastrophes and Recoveries in the Holocene29 August-2 September, West London, UKContact: http://www.brunel.ac.uk/depts/geo/CatastrophesUnited

Climate Variability, Predictability and Climate Risks7-14 September, Bernese Oberland, SwitzerlandContact: nccr-climate@giub.unibe.ch orhttp://www.ncccr-climate.unibe.ch

IGAC: “Atmospheric Chemistry in the Earth System: From Regional Pollution to Global Climate Change”18-25 September, Crete, GreeceContact: http://atlas.chemistry.uch.gr/IGAC2002/

JGOFS: 17th JGOFS Scientifi c Steering Committee Meeting and capacity building/training course on ocean biogeochemistry23-25 September, Concepción, ChileContact: Roger Hanson, Roger.Hanson@jgofs.uib.no

Cave Climate and Paleoclimate- Best Record of the Global Change24-27 September, Stara Zagora, BulgariaContact: P.Delchev@Museum.web.bg

START: START SARCS meeting to be held in conjunction with START/WOTRO/APN26-28 September, Hanoi, Vietnam (tentative)Contact: C.H. Liu, chliu@cc.ncu.edu.tw

START: START/WOTRO/APN Southeast Asian Regional Seminar on Building Adaptive Capacity to Global Environmental Change: making better use of research-based knowledge to improve decision making26-28 September, Hanoi, Vietnam (tentative)Contact: Nguyen Hoang Tri, nguyenhoangtri@hn.vnn.vn

International Symposium on “Land Use, Nature Conservation, and the Stability of Rainforest Mar-gins in Southeast Asia’s29 September-3 October, Bogor, IndonesiaContact: symp2002@gwdg.de

26th SCOR General Meeting1-5 October, Sapporo, JapanContact: SCOR Secretariat, scor@jhu.edu

GLOBEC: ICES ASC (ICES Centenary)1-5 October, Copenhagen, DenmarkContact: ICES Secretariat, ices.info@ices.dk

START: APN/TEA Workshop on Global Change and Sustainable Development in the Coastal Northeast Asia2-4 October, Vladivostok, Russia (tentative)Contact: Vladimir Kasyanov, inmarbio@mail.primorye.ru

START: START TEACOM meeting2-4 October, Vladivostok, Russia (tentative)Contact: Congbin Fu, sec@tea.ac.cn

International Workshop on Reducing Vulnerability of Agriculture and Forestry, Climate Variability and Climate Change6-9 October, Ljubliana, SloveniaContact: Dr. Sivakumar, Sivakumar_M@gateway.wmo.ch

IGBP: 15th IGBP Offi cers Meeting7-10 October, Casablanca, MoroccoContact: Clemencia Widlund, clemencia@igbp.kva.se

GLOBEC: GLOBEC WG Meetings13-14 October, Qingdao, P.R. ChinaContact: GLOBEC IPO, globec@pml.ac.uk

START: 16th START Scientifi c Steering Committee Meeting14-16 October, TBAContact: Ching Wang, xwang@agu.org

GLOBEC: GLOBEC SSC Meeting14 October (pm). and 19-20 October, Qingdao, P.R. ChinaContact: GLOBEC IPO, globec@pml.ac.uk

GLOBEC: OSM2 - 2nd GLOBEC Open Science Meeting15-18 October, Qingdao, P.R. ChinaContact: http://www.pml.ac.uk/globec/

IGBP: Scoping Meeting for the Land-Atmosphere Project16-18 October, TBAContact: Almut Arneth, arneth@dkrz.de

GLOBEC: Joint GLOBEC Foci WG/PICES Task Team Meetings19 October (am), Qingdao, P.R. ChinaContact: GLOBEC IPO, globec@pml.ac.ukPICES Secretariat, secretariat@pices.int

33

GLOBEC: PICES XI21-26 October, Qingdao, P.R. ChinaContact: PICES Secretariat, secretariat@pices.int

IGFA (International Group of Funding Agencies) Plenary Meeting23-25 October, Norwich, UKContact: Carola, Roeser, carola.roeser@dlr.de

GLOBEC: IOC/SPACC Study Group Workshop on the Use of Environmental Indices in the management of pelagic fi shDecember, TBAContact: Manuel Barange, m.barange@pml.ac.uk

JGOFS: Continental Margin Task Team Workshop for the Global Synthesis of the 5 Regional Syntheses4-6 December, Washington DC, USAContact: Larry Atkinson, atkinson@ccpo.odu.edu, Renato Quiño-nes, rquinone@udec.cl; Richard Jahnke, rick@skio.peachnet.edu

SOLAS: 2nd SOLAS SSC Meeting11-13 December, San Francisco, USAContact: Peter Liss

2003

IGBP: 18th SC Meeting20-24 January, Punta Arenas, ChileContact: Clemencia Widlund, clemencia@igbp.kva.se

International symposium “Environmental Change in Central Asia: Climate, Geodynamics, Evolution, Human Impact”10-15 March, Berlin, GermanyContact: Bernd Wünnemann, wuenne@zedat.fu-berlin.de

JGOFS: 18th JGOFS Scientifi c Steering Committee Meeting5-8 May, Washington DC, USAContact: Roger Hanson, Roger.Hanson@jgofs.uib.no

JGOFS: 3rd JGOFS Open Science Conference5-8 May, Washington DC, USAContact: Roger Hanson, Roger.Hanson@jgofs.uib.noKen Buesseler, kbuesseler@whoi.edu

IGBP: 3rd IGBP Congress19-25 June, Banff, CanadaContact: Clemencia Widlund, clemencia@igbp.kva.seCharlotte Wilson, charlottew@igbp.kva.se

Synthesis and Futures Meeting 29 May-01 June

Miami, Florida, USA

For further information contact the

LOICZ International Project Offi ce,

E-mail: loicz@nioz.nl

Tel: 31-222 369 404

Land-Ocean Interactions in the Coastal Zone

www.nioz.nl/loicz/

Next issue“We are entering a new and exciting period for IGBP. After a short transition period, we should soon develop new research foci and methodologies…. Although disciplinary aspects (includ-ing process studies) will remain an important part of the scientifi c agenda, attempts will be made to address scientifi c questions through a more integrated approach, recognizing that the Earth is a nonlinear system with chaotic behavior, feedback mechanisms, bifurcation points, etc., and that the prediction of its future evolution is not always deterministic.”

Guy Brasseur, Chair, IGBP

The next issue of the Global Change NewsLetter will focus on the transition of IGBP towards its new set of questions, new structure, and innovative research approaches. Articles will report on the latest develop-ments in the scientifi c planning for the next decade of IGBP work, and will provide a useful roadmap for both the science and the programmatics for IGBP II.

First Announcement of

International Open Science Meetingon Ocean Biogeochemistry and Ecosystems

January 2003Paris, France

The International Geosphere-Biosphere Programme (IGBP) and the Scientifi c Committee on Oceanic Research (SCOR) announce an open science meeting on Ocean Biogeochemistry and Ecosystems.

The meeting will be held in Paris in Januari 2003. The purpose of the meeting is to defi ne the next phase of international global change research on marine biogeochemistry and interactions with ecosystems.

More detailed information about the meeting can be found on:

www.igbp.kva.se/obe/

International Geosphere-Biosphere ProgrammeScientifi c Committee on Oceanic Research

Edited by Clare Bradshaw

Technical Editing by John Bellamy

Layout by Petra Nilsson

Requests for reproduction of articles appearing in this distribution should be addressed to the Editor:

(E-mail: sec@igbp.kva.se)

NewsLetter requests and change of address information should be sent to:

IGBP Secretariat The Royal Swedish Academy of Science Box 50005, S-104 05 Stockholm, Sweden

Tel: (+46-8) 16 64 48

Fax: (+46-8) 16 64 05

E-mail: sec@igbp.kva.se

http://www.igbp.kva.se

The IGBP Report Series is published in annex to the Global Change NewsLetter

ISSN 0284-5865

Note to contributorsArticles for “Science Features” should achieve a balance of (i) solid scientifi c content, and (ii) appeal for the broad global change research and policy communities rather than to a narrow discipline. Articles should be between 800 and 1500 words in length, and be accompanied by one to three key graphics or fi gures (colour or black and white).

Contributions for “Discussion Forum” should be between 500 and 1000 words in length and address a broad issue in global change science. A “Discussion Forum” article can include up to 2 fi gures.

Contributions for ‘Integration’ should be between 800-1200 words in length and highlight how IGBP or its core projects are integrating with other areas of Earth System Science. The arti-cle can include up to two fi gures.

“Correspondence” should be no more than 200 words and be in the form of a Letter to the Editor in response to an article in a previous edition of the Newsletter or relating to a specifi c global change issue. Please include author and contact details.

Required Image Quality for IGBP PublicationsPhotographic images should be saved in TIFF format. All other images including charts, graphs, illustrations, maps and logos should be saved in EPS format. All pixel images need to be high resolution (at least 300 pixels per inch).

Some charts graphs and illustrations can be reconstructed at the IGBP Secretariat, however, poor quality photographic images, maps and logos cannot be improved. Material “bor-rowed” from the Internet cannot be used for publication, as it does not fi t the requirements listed above.

If you have queries regarding image quality for the Global Change NewsLetter please contact John Bellamy E-mail: john@igbp.kva.se

Please note: fi gures of any kind must either be original and unpublished, or (if previously published) the author(s) must have obtained permission to re-use the fi gure from the original publishers. In the latter case, an appropriate credit must be included in the fi gure caption when the article is submitted.

Deadlines for 2002:June issue Deadline for material: May 10 (special edition on IGBP Phase II)

September issue Deadline for material: August 9

December issue Deadline for material: November 1

Send contributions by email to the Editor, Clare Bradshaw E-mail: clare.bradshaw@igbp.kva.se; Phone: +46 8 6739 593; Reception: +46 8 16 64 48; Fax: +46 8 16 64 05

Next edition of the IGBP Newsletter…

• Special edition on IGBP Phase II